Handheld x-ray system interface with tracking feature

ABSTRACT

In one embodiment, an X-ray system includes a handheld X-ray interface device. The handheld X-ray interface device includes a wireless interface for communicating with an imaging system and a tracking device configured to provide a location and/or to track movement of the handheld X-ray interface device relative to the imaging system, wherein the location or tracked movement of the handheld X-ray interface device is communicated to the imaging system as an input for at least one control function of the imaging system.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to X-ray imaging systems andmore particularly to X-ray imaging systems that use a handheld interfacedevice.

X-ray systems are widely employed in medical environments, such ashospitals. Typically, where possible the X-ray technician is positionedaway from the location of exposure, and often behind a shielded barrierto avoid or reduce exposure to radiation. Often the X-ray systemsinclude an exposure switch, or handswitch, attached to a cord, which isin signal communication with a control console of the X-ray system andthat allows the technician to make the exposure from a distance (e.g.,by pressing a button on the handswitch), sometimes outside of theexamination room.

Often patients undergoing X-ray examinations are positioned in difficultor awkward positions for a variety of reasons. The technician mustadjust the X-ray system accordingly. However, when the technician is notphysically in close proximity to the X-ray system it may be difficultfor the technician to interact with the X-ray system. In addition, thetechnician must return to the console between every exposure to analyzethe imaging data and to determine if the patient was properly positionedor if the X-ray source was properly aligned with a detector. Thetechnician may have to expose the patient to needless exposures intrying to obtain the optimal image. Thus, the need for a handswitcharrangement to overcome these difficulties.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one embodiment, an X-ray system includes an imagingsystem. The imaging system includes a source of X-ray radiation, anX-ray image receptor, control circuitry for controlling the source ofX-ray radiation, and a wireless interface. The X-ray system alsoincludes a handheld interface device configured to communicatewirelessly with the imaging system. The imaging system is configured totrack a location of the handheld interface device and to use thelocation as an input for at least one control function of the imagingsystem.

In accordance with another embodiment, an X-ray system includes ahandheld X-ray interface device. The handheld X-ray interface deviceincludes a wireless interface for communicating with an imaging systemand a tracking device configured to provide a location and/or to trackmovement of the handheld X-ray interface device relative to the imagingsystem, wherein the location or tracked movement of the handheld X-rayinterface device is communicated to the imaging system as an input forat least one control function of imaging system.

In accordance with a further embodiment, a method for tracking thelocation of a handheld interface device includes establishing wirelesscommunication between an imaging system and a handheld interface device,the imaging system includes a source of X-ray radiation, an X-raydetector, control circuitry for controlling the source of X-rayradiation, and a first wireless interface, the handheld interface deviceincludes a second wireless interface for communicating wirelessly withthe imaging system and a tracking device configured to provide alocation and to track movement of the handheld interface device. Themethod also includes transmitting the location or tracked movement ofthe handheld interface device relative to the imaging system.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a perspective view of a fixed X-ray system, equipped inaccordance with aspects of the present technique;

FIG. 2 is a perspective view of a mobile X-ray system, equipped inaccordance with aspects of the present technique;

FIG. 3 is a diagrammatical overview of the X-ray systems in FIGS. 1 and2;

FIG. 4 is a perspective view of a handheld interface device in FIGS. 1and 2;

FIG. 5 is a perspective view of another handheld interface device inFIGS. 1 and 2;

FIG. 6 is a diagrammatical overview of the handheld interface device inFIG. 4;

FIG. 7 is a diagrammatical overview of the handheld interface device inFIG. 5;

FIG. 8 is a diagrammatical overview of system operational data receivedby handheld interface devices, in accordance with aspects of the presenttechnique;

FIG. 9 is a diagrammatical overview of user-input and user-inputcommands received and transmitted by handheld interface devices, inaccordance with aspects of the present technique;

FIG. 10 is a perspective view of an imaging system and handheldinterface device outside of a desired distance from each other, inaccordance with aspects of the present technique;

FIG. 11 is a perspective view of the imaging system following thehandheld interface device, in accordance with aspects of the presenttechnique;

FIG. 12 is a perspective view of movement of an X-ray source of theimaging system by the handheld interface device, in accordance withaspects of the present technique;

FIG. 13 is a perspective view of the imaging system conducting animaging sequence in response to the handheld interface device, inaccordance with aspects of the present technique;

FIG. 14 is a perspective view of determining various exposure parametersusing the handheld interface device, in accordance with aspects of thepresent technique;

FIG. 15 is a perspective view of determining orthogonality between theX-ray source and the image receptor, in accordance with aspects of thepresent technique;

FIG. 16 is perspective view of various patient data displayed on thehandheld interface device, in accordance with aspects of the presenttechnique;

FIG. 17 is a perspective view of selection of desired area for imagingusing the handheld interface device, in accordance with aspects of thepresent technique;

FIG. 18 is a flow diagram of a method for operating the handheldinterface device, in accordance with aspects of the present technique;

FIG. 19 is a flow diagram of another method for operating the handheldinterface device, in accordance with aspects of the present technique;

FIG. 20 is a flow diagram of a method for viewing patient data on thehandheld interface device, in accordance with aspects of the presenttechnique; and

FIG. 21 is a flow diagram of a method for tracking the location of thehandheld interface device, in accordance with aspects of the presenttechnique.

DETAILED DESCRIPTION OF THE INVENTION

Referring generally to FIG. 1, an X-ray system is represented,referenced generally by reference numeral 10. In the illustratedembodiment, the X-ray system 10 may be a digital or analog X-ray system.The X-ray system 10 is designed both to acquire original images or imagedata and to process the image data for display (in a digital X-raysystem) in accordance with the present technique.

In the embodiment illustrated in FIG. 1, the X-ray system 10 includes animaging system 12. The imaging system 12 includes an overhead tubesupport arm 14 for positioning a radiation source 16, such as an X-raytube, and a collimator 18 with respect to a patient 20 and an imagereceptor 22. In analog X-ray systems 10, the image receptor 22 mayinclude a radiographic film and cassette, phosphorescent screen andcomputed radiography cassette, or other device. In digital X-raysystems, the image receptor 22 may include a digital X-ray detector. Theimaging system 12 may also include a camera 24 to help facilitate thepositioning of the radiation source 16 and collimator 18. Moreover, inone embodiment, the imaging system 12 may be used in consort with one orboth of a patient table 26 and a wall stand 28 to facilitate imageacquisition. Particularly, the table 26 and the wall stand 28 may beconfigured to receive image receptor 22. For instance, image receptor 22may be placed on an upper, lower or intermediate surface of the table26, and the patient 20 (more specifically, an anatomy of interest of thepatient 20) may be positioned on the table 26 between the image receptor22 and the radiation source 16. Also, the wall stand 28 may include areceiving structure 30 also adapted to receive the image receptor 22,and the patient 20 may be positioned adjacent the wall stand 28 toenable the image or image data to be acquired via the image receptor 22.The receiving structure 30 may be moved vertically along the wall stand28.

Also depicted in FIG. 1, the imaging system 12 includes a workstation 32and display 34. In one embodiment, the workstation 32 may include orprovide the functionality of the imaging system 12 such that a user 36,by interacting with the workstation 32 may control operation of thesource 16 and detector 22 (in a digital X-ray system 10). In otherembodiments, the functions of the imaging system 12 may bedecentralized, such that some functions of the imaging system 12 areperformed at the workstation 32, while other functions are performed byanother component of the X-ray system 10, such as a handheld interfacedevice 38. The handheld interface device 38 is configured to be held bya user 36 and to communicate wirelessly with the imaging system 12. Thehandheld interface device 38 is also configured to prepare the imagingsystem 12 for an exposure and to initiate an exposure. The imagingsystem 12 is configured to wirelessly communicate system operationaldata to the handheld interface device 38 and the handheld interfacedevice 38 is configured to provide a user detectable indication of theoperational status based on the data. In one embodiment, the handheldinterface device 38 (e.g., 40) is simply designed to prepare andinitiate an exposure, as well as to receive system operational data andto provide an indication of the data. It is noted that the imagingsystem 12 and handheld interface device 38 may utilize any suitablewireless communication protocol, such as an IEEE 802.15.4 protocol, anultra wideband (UWB) communication standard, a Bluetooth communicationstandard, or any IEEE 802.11 communication standard.

In another embodiment, the handheld interface device 38 (e.g., 42) isconfigured to receive a user-input command for operation of the imagingsystem 12 (e.g., changing X-ray source settings or moving the receivingstructure 30 along the wall stand 28) prior to initiation of an X-rayexposure sequence and to wirelessly transmit the command to the imagingsystem 12. For example, the imaging system 12 may include a speaker 44to transmit patient-audible commands to the patient 20 in response to asignal from the handheld interface device 42. The speaker 44 may belocated on the operator workstation 34, near the radiation source 16, inthe table 26, or another location. In response to wirelessly receivingthe command from the handheld interface device 42 the imaging system 12executes the command. Also, the handheld interface device 42 includes auser-viewable screen 46 and is configured to receive and display patientdata on the screen 46. The imaging system 12 is configured tocommunicate patient data or instructions to the handheld interfacedevice 42. In one embodiment, the workstation 32 may be configured tofunction as a server of instructions and/or content on a network 48 ofthe medical facility, such as a hospital information system (HIS), aradiology information system (RIS), and/or picture archivingcommunication system (PACS), and to provide these instructions and/orcontent to the handheld interface device 42. Alternatively, the network48 may wirelessly communicate directly with the handheld interfacedevice 42.

Further, the handheld interface device 42 may be configured to betracked by the imaging system 12. The imaging system 12 is configured totrack the location and/or movement of the handheld interface device 42and to use the location and/or movement as input to control at least onefunction of the system 12 (e.g., movement of the X-ray source 16).

In one embodiment, the imaging system 12 may be a stationary systemdisposed in a fixed X-ray imaging room, such as that generally depictedin and described above with respect to FIG. 1. It will be appreciated,however, that the presently disclosed techniques may also be employedwith other imaging systems, including mobile X-ray units and systems, inother embodiments.

For instance, as illustrated in the X-ray system of FIG. 2, the imagingsystem 12 may be moved to a patient recovery room, an emergency room, asurgical room, or any other space to enable imaging of the patient 20without requiring transport of the patient 20 to a dedicated (i.e.,fixed) X-ray imaging room. The imaging system 12 includes a mobile X-raybase station 50 and image receptor 22. As mentioned above, the X-raysystem 10 may be digital or analog. In one embodiment, a support arm 52may be vertically moved along a support column 54 to facilitatepositioning of the radiation source 16 and collimator 18 with respect tothe patient 20. Further, one or both of the support arm 52 and supportcolumn 54 may also be configured to allow rotation of the radiationsource 16 about an axis. The X-ray base station 50 may also includecamera 24 to assist in positioning of the radiation source 16 andcollimator 18, as well as speaker 44 to transmit patient-audiblecommands as described above. In addition, the X-ray base station 50includes a speaker located either on a base unit 56, the column 54, orthe arm 52, or another location of the X-ray base station 50. Further,the X-ray base station 50 has a wheeled base 58 for movement of thestation 50.

The patient 20 may be located on a bed 60 (or gurney, table or any othersupport) between the X-ray source 24 and the image receptor 22 andsubjected to X-rays that pass through the patient 20 and are received byeither a film, phosphorescent screen, or other medium. During an imagingsequence using the digital X-ray system 10, the detector 22 receivesX-rays that pass through the patient 20 and transmits imaging data to abase unit 56. The detector 22 is in communication with the base unit 56.The base unit 56 houses systems electronic circuitry 62 that acquiresimage data from the detector 22 and that, where properly equipped, mayprocess the data to form desired images. In addition, the systemselectronic circuitry 62 both provides and controls power to the X-raysource 16 and the wheeled base 58 in either the digital or analog X-raysystem 10. The base unit 56 also has the operator workstation 32 anddisplay 34 that enables the user 36 to operate the X-ray system 10. Theoperator workstation 32 may include buttons, switches, or the like tofacilitate operation of the X-ray source 16 and detector 22.

Similar to the X-ray system 10 in FIG. 1, functions of the imagingsystem 12 may be performed by the handheld interface device 38. Asdescribed above, the imaging system 12 and the handheld interface device38 are configured to communicate wirelessly with each other. Inaddition, the handheld interface device 38 can be configured tocommunicate wirelessly with the medical facility network 48, asdescribed above. As above, the user 36 may utilize the handheldinterface device 40 designed to prepare and initiate an exposure, aswell as to receive system operational data and to provide an indicationof the data. Alternatively, the user 36 may utilize the handheldinterface device 42, described above, to input user commands foroperation of the imaging system 12 (e.g., the movement of the X-ray basestation 50). In addition, the handheld interface device 42 includesscreen 46 for the display of patient data, image data (in digitalsystems 10), instructions, as well as other information. Further, thehandheld interface device 42 may be configured to be tracked, asdescribed above. Tracking of the handheld interface device 42 mayprovide input to the X-ray base station 50 to follow the handheldinterface device 42 as described below. The X-ray base station 50 has aholder or cradle 64 for the handheld interface device 38 when the device38 is not in use. The cradle 64 may be configured to recharge thebattery of the handheld interface 38, either through conductive chargecontacts or with a contactless method such as inductive or capacitivecharging.

FIG. 3 illustrates diagrammatically the X-ray systems 10 described inFIGS. 1 and 2, in particular, digital X-ray systems 10, although some ofthe below description applies to analog X-ray systems 10 as well. Asillustrated in FIG. 3, the X-ray system 10 includes the source of X-rayradiation 16 positioned adjacent to the collimator 18. A light source66, also known as a collimator light, is positioned between the X-raysource 16 and the collimator 18. The collimator 18 permits a stream ofradiation 68 or light to be directed to a specific region in which anobject or subject, such as the patient 20, is positioned. A portion 70of the radiation passes through or around the subject and impacts theimage receptor or digital X-ray detector 22. As will be appreciated bythose skilled in the art, the detector 22 in digital X-ray systems 10converts the X-ray photons received on its surface to lower energyphotons, and subsequently to electric signals, which are acquired andprocessed to reconstruct an image of the features within the subject.The collimator light 66 in the collimator 18 directs light onto the samearea where the X-ray photons will pass and can be used to position thepatient 20 before exposure. The collimator light 66 can be turned on andoff with a user input on the imaging system 12 or on the handheldinterface device 38.

Moreover in digital X-ray systems, the detector 22 is coupled to adetector controller 72 which commands acquisition of the signalsgenerated in the detector 22. The detector controller 26 may alsoexecute various signal processing and filtration functions, such as forinitial adjustment of dynamic ranges, interleaving of digital imagedata, and so forth. The detector controller 26 is responsive to signalsfrom control circuitry 74 communicated wirelessly via a wirelessinterface 76. In general, the control circuitry 74 commands operation ofthe imaging system 12 to execute examination protocols and to processacquired image data (in digital X-ray systems 10). In the presentcontext, the control circuitry 74 also includes signal processingcircuitry, typically based upon a programmed general purpose orapplication-specific digital computer; and associated devices, such asoptical memory devices, magnetic memory devices, or solid-state memorydevices, for storing programs and routines executed by a processor ofthe computer to carry out various functionalities, as well as forstoring configuration parameters and image data; interface circuits; andso forth.

In both digital and analog X-ray systems 10, the radiation source 16 iscontrolled by the control circuitry 74 which controls signals forexamination sequences. For example, the control circuitry 74 can inhibitthe operation of the radiation source 16 if the correct examinationconditions are not in place. In addition, the control circuitry 74controls a power supply 78 which supplies power to the radiation source16, light source 66, camera 24, as well the control circuitry 74.Interface circuitry 80 facilitates the provision of power to theradiation source 16, light source 66, camera 24, and control circuitry74. The power supply 78 also provides power to a mobile drive unit 82(in mobile X-ray systems) to drive the movement of the wheeled base 58of the X-ray base station 50.

In the embodiment illustrated in FIG. 1, the control circuitry 74 islinked to at least one output device, such as the display or printer 34.The output device may include standard or special purpose computermonitors and associated processing circuitry. One or more operatorworkstations 34 may be further linked in the system for outputtingsystem parameters, requesting examinations, viewing images (in digitalX-ray systems 10), and so forth. In general, displays, printers,workstations, and similar devices supplied within the system may belocal to the imaging components, or may be remote from these components,such as elsewhere within an institution or hospital, or in an entirelydifferent location, linked to the imaging system 12 via one or moreconfigurable networks, such as the Internet, virtual private networks,and so forth. The control circuitry 74 may also be linked to the speaker44 which provides audible signals such as locator signals orpatient-audible commands.

Via the wireless interface 76 the imaging system 12 communicateswirelessly with the handheld interface device 38. The control circuitry74 provides the handheld interface device 38 system operational data(e.g., inhibit of operation of radiation source), images reconstructedfrom image data from the detector 22 (in digital X-ray systems 10),images of the patient 20 generated by the camera 24, and patient data,as well as other information. The handheld interface device 38wirelessly communicates a signal to prepare for and initiate an exposureand other commands for operation of the imaging system 12, as well thelocation and/or movement of the device 38 relative to the system 12.Besides receiving patient data and/or instructions from the imagingsystem 12, the handheld interface device 38 wirelessly receives patientinformation and/or instructions (e.g., imaging sequences to beperformed) from the medical facility's network 48. The medical facilitynetwork 48 includes PACS 84, RIS 86, and/or HIS 88 to provide theinformation and/or instructions. The network 48 may also communicate thepatient information and/or instructions to imaging system 12, which maythen provide the information and/or instructions to the handheldinterface device 38.

As mentioned above, the handheld interface device 38 may include asimple embodiment of the device 40 to prepare for and initiate anexposure, as well as to receive system operational data and to providean indication of the data. In addition, the handheld interface device 40is configured to provide user detectable indications of the operationalstatus of the imaging system 12. FIG. 4 illustrates the handheldinterface device 40 of FIGS. 1 and 2. The handheld interface device 40includes an exterior housing 90 that is suitably dimensioned to fit inthe hand of the user. The handheld interface device 40 can be configuredto be paired with a single X-ray system 10. The handheld interfacedevice 40 is configured to provide user detectable indications of theoperational status of the imaging system 12. The handheld interfacedevice 40 includes a prepare/exposure push button 92 located at the top94 of the device 40. The prepare/exposure button 92 may operate in avariety of ways. In one embodiment, pressing the button 92 a first timemay prepare the X-ray system 10 for an exposure (i.e., the rotorencasing the radiation source 16 begins spinning). Pressing the button92 a second time may initiate the exposure by the X-ray system 10. Thebutton 92 may be inhibited from being pressed the second time if theX-ray system 10 has not finished preparations for the exposure.Alternatively, the button 92 may be partially pressed to a firstposition to prepare the X-ray system 10 for the exposure and furtherpressed to a second position to initiate the exposure. The button 92 maybe inhibited from being pressed to the second position if the X-raysystem 10 has not finished preparations for the exposure. In eitherembodiment, the button 92 is configured to not command the system toinitiate an exposure when the operation of X-ray source 16 is inhibited.The handheld interface device 40 also includes a collimator light button96 disposed on the exterior housing 90. Pressing the collimator lightbutton 96 may command the system to activate or deactivate thecollimator light 66. The handheld interface device 40 is configured togo to sleep when not in use. Pressing the prepare/exposure 92 and/orcollimator light button 96 may also shift the device 40 from sleep modeto operational mode. In other embodiments, the handheld interface device40 may include additional buttons for other features.

The handheld interface device 40 may also include one or more lightemitting diodes (LEDs) to indicate the operational status of the imagingsystem 12. For example, the handheld interface device 40 may include apower status (battery status) LED 98 to indicate the power level of thedevice 40. The power status LED 98 may indicate the power status of thedevice 40 in a variety of ways. For example, the power status LED 98 mayonly illuminate when the device 40 has sufficient power. If the device40 has low power, the LED 98 may blink or not be illuminated.Alternatively, the LED 98 may only illuminate when the power of thehandheld interface device 40 is low. In a further alternative, the LED98 may illuminate a specific color for a specific power status of thedevice 40, such as green for sufficient power and red for low power. Thehandheld interface device 40 can also include a charge status LED 100for the battery or power supply 78 that powers the X-ray source 16and/or mobile drive unit 82 of the imaging system 12. The LED 100 may bedesigned to function similarly to the power status LED 98 to indicatethe status of the power supply 78. The handheld interface device 40 alsoincludes an X-ray exposure LED 102 to indicate when an exposure by theimaging system 12 is occurring. The LED 102 of the device 40 illuminatesduring the exposure. An LED 101 could indicate an inhibit on the imagingsystem 12 that currently prevents exposure initiation. An LED 103 couldindicate that wireless communication is occurring. A combination of theLEDs could indicate that the wireless handheld interface device 40 is inthe process of or has completed association or pairing with imagingsystem 12. Alternative embodiments may include additional LEDS toprovide an indication of system operation data. The handheld interfacedevice 40 also includes a speaker 104. The speaker 104 can provide anaudible tone or tone sequence during the occurrence of the exposure.Also, the speaker 104 may provide an audible tone for a locator signalas described below.

FIG. 5 illustrates the handheld interface device 42 of FIGS. 1 and 2that includes similar and additional features. The handheld interfacedevice 42 may be based upon or include a personal digital assistant, amultipurpose cellular telephone, or other handheld device. The handheldinterface device 42 includes an exterior housing 90 that is suitablydimensioned to fit in the hand of the user. The handheld interfacedevice 42 is configured to be paired with the single X-ray system 10 andto provide user detectable indications of the operational status of theimaging system 12. In addition, the handheld interface device 42 isconfigured to receive a user-input command for operation of the imagingsystem 12, as well as patient data and/or instructions. Further, thehandheld interface device 42 is configured to have the location and/ormovement of the device 42 tracked by the imaging system 12 to be used bythe system 12 as an input for one or more control functions of thesystem 12. The handheld interface device 42 includes screen 46 and acombination of buttons and LEDs to interact with the imaging system 12.The screen 46 is configured display system operational data and X-raysystem or exposure settings. For example, the screen 46 may display theexposure parameters such as a kilovolt peak setting 106, a milliampsetting 108, or other settings such as a milliamp-second setting. Thescreen 46 may include one or more icons 110 that represent systemoperational data. For example, the icons 110 may represent the chargestatus of the power supply 78 to the X-ray source 16 and/or mobile driveunit 82, power status of the device 42, readiness of X-ray system 10 forexposure, inhibition of the X-ray source 16, an exposure in progress, awireless link connection, and other operational data. The screen 46 isalso configured to display patient data, instructions, and images. Thehandheld interface device 42 may also include LEDS to indicate systemoperational data as described with device 40. For example, LED 112 mayilluminate when an exposure is in progress.

Additionally, the handheld interface device 42 may include buttons 114and 116, which may be actual depressible switches, regions of a touchscreen, or any other suitable user interface. The buttons 114 and 116may be used to input commands for the imaging system 12 to execute.These commands may be used for multiple functions when pressed,including preparing and initiating an exposure by the system 12,operating the collimator light 66, inputting the location of the device42 with respect to the system 12 (e.g., to calculate a source-to-imagedistance), and other functions. The buttons 114 and 116 when used as aprepare/expose button may not be pressed when operation of the X-raysource 16 is inhibited.

In addition, the screen 46 of the handheld interface device 42 mayinclude a touch-screen to allow the user to interface with the system 12and to input commands for the operation of the system 12. The screen 46may allow the user to select from a variety of modes to operate theimaging system 12. For example, the screen 46 may include exposureparameters 106 and 108, described above, as well as arrows 118 to changethe settings of the exposure parameters 106 and 108. Instead of thebuttons 114 and 116, the screen 46 may be used to prepare for andinitiate the system 12 for an exposure. Further, the handheld interfacedevice 42 includes a speaker/recorder 120. The speaker 120 provides anaudible tone during exposures. Also, the speaker 104 may provide anaudible tone for a locator signal as described below. Further, thespeaker 104 may serve as a microphone, or a separate microphone (notshown) may be provided and the device configured to act as a recorder toallow the user to dictate voice inputs. The voice inputs may then berecorded by the device 42 and/or in the X-ray system 10, the HIS, RIS orPACS and associated with an X-ray imaging sequence.

FIG. 6 illustrates a diagrammatical overview of the handheld interfacedevice 40. The handheld interface device 40 includes a control circuitry122 to control the various functions of the device 40 and a wirelessinterface 124 to communicate with the imaging system 12. The wirelessinterface 124 may utilize any suitable wireless communication protocol,such as an IEEE 802.15.4 protocol, an ultra wideband (UWB) communicationstandard, a Bluetooth communication standard, or any IEEE 802.11communication standard. The control circuitry 122 includes a processor126 to process the various signals received via the wireless interface124 from the system 12. In addition, the processor 126 receives inputsignals from input devices and generates command signals to betransmitted to the system 12 via the wireless interface 124. The controlcircuitry 122 also includes a memory 128 for storing programs androutines executed by the processor 126, as well as configurationparameters of the handheld interface device 40. The processor 126 andmemory 128 are connected to interface circuitry 130 that interacts withthe input and output devices of the handheld interface device 40 toreceive input signals from the input devices and to transmit outputsignals to the output devices and/or wireless interface 124.

The control circuitry 122 is powered and in communication with a powersupply 132. The power supply 132 may be a rechargeable battery (e.g., athin film battery). The power supply 132 includes a charging interface134 configured for charging of the power supply 132 when the handheldinterface device 40 is located in a charger (e.g., the cradle 64 of theX-ray base station 50). The charge cradle 64 can charge the power supply132 of the handheld interface device 40 either through conductive chargecontacts or through inductive or capacitive contactless chargingmethods. Alternatively, the power supply 132 may include photovoltaiccells to recharge the handheld interface device 40. Further, the powersupply 132 may include a device to harvest radiofrequency energy orpiezoelectric energy (e.g., microelectricalmechanical system (MEMS)device).

The interface circuitry 130 receives system operational data from thesystem 12 via the wireless interface 124 and transmits the data to theprocessor 126. Once the data is processed a signal is generated by theprocessor 126 and transmitted via the interface circuitry 130 to theoutput devices. For example, the handheld interface device 40 mayreceive a command from imaging system 12 to locate the device 40. Thespeaker 104 may generate a locator signal in response to the command.The speaker 104 may also generate a user audible tone when an exposureis taking place. The speaker 104 may generate an audible tone if thehandheld device 40 is out of the charge cradle 64 for a minimum time.Also, various LEDS 136 may be illuminated to provide the user anindication of the system operational status as described above. Further,besides a visual and audible indication of an exposure, the handheldinterface device 40 includes a vibrating motor 138 to vibrate andprovide a tactile indication of the occurrence of an exposure inprogress.

The handheld interface device 40 also provides commands to the imagingsystem 12. For example, as described above, the device 40 may include acollimator light button 96 to activate and deactivate the collimatorlight 66, and the prepare/expose button 92 to prepare and initiateexposures with the system 12. Input signals received from these buttons140, 92, and 96 generate command signals wirelessly transmitted to thesystem 12 for execution. The handheld interface device 40 may includeother devices 142 besides the input and output devices described foroperation of the device 40. For example, other devices 142 may include atracking device, as described below, or a flash light.

FIG. 7 illustrates a diagrammatical overview of the handheld interfacedevice 42. The handheld interface device 42 includes control circuitry122, power supply 132, and wireless interface 124 similar to theembodiment in FIG. 6. However, the memory 128 is also capable of storingimages transmitted from the imaging system 12 (in digital X-ray systems10), patient data/and or instructions received from the system 12 ornetwork 48, system operational data (e.g., dose area product to beembedded in image sequences), and user input (e.g., audible recordingsto be associated with an imaging sequence). As described above, thehandheld interface device 42 includes one or more LEDS 136 to provideuser detectable indications of the system operational data of theimaging system 12.

The handheld interface device 42 also includes the screen 46 to displaysystem operational data, such as in the form of icons 110 as shown inFIG. 5. The system operational data may also be displayed in other formson the screen 46 (e.g., textual or numerical form). For example,exposure parameter settings 106 and 108 may be presented on the screen46. The screen 46 may also include a touch-screen 46 capable of encodinginputs by touch. For example, a gesture on the touch-screen 46 (e.g.,pressing an arrow displayed on the touch-screen 46 in FIG. 5) may beuser input. In some embodiments, the gesture may be interpreted as amulti-point gesture. Images of the patient 20 received via the camera 24or network 48 may also be displayed on the screen 46. Alternatively, astill image of the patient 20 or a generic image of an anatomical regionof the patient 20 may also be displayed on the screen 46. The user maybe able to input a location on the anatomy of the patient 20 to beimaged by touching the portion of the anatomy on the touch-screen 46, asdescribed below.

Also, as described above, the device 42 may include a speaker/recorder120. The speaker 120 allows for the output of an audible tone or tonesequence during an exposure. In addition, the speaker 120 may output alocator signal in response to a command from the imaging system 12 tolocate the device 42. The speaker 120 also allows the recording ofuser-dictated voice inputs that may be recorded and stored in the memory128 for association with an X-ray image sequence. Also, theuser-dictated voice input may be transmitted via the wireless interface124 to the imaging system 12 to be emitted for the hearing of thepatient 20 undergoing X-ray imaging.

As mentioned above, the handheld interface device 42 may include buttons114 and 116 to allow the user to make various inputs. For example, thebuttons 114 and 116 may be used to prepare and initiate an exposure oroperate the collimator light 66. Alternatively, these functions, as wellas others, may be carried out using inputs via the touch-screen 46. Thebuttons 114 and 116 may be used in conjunction with other devices of thehandheld interface device 142. For example, the device may include atracking device 144. The tracking device 144 may comprise variousinertial measurement units such as an accelerometer, a magnetometer, aninclinometer, and/or a gyroscope. These inertial measurement units allowthe relative position and rotation of the device 42 to be tracked in a3-D coordinate system. The imaging system 12 is configured to track thelocation and/or movement of the device 42 as received from the trackingdevice 144 via the wireless interface 124. The location and/or movementof the device 42 are used as input to control functions of the system12. The tracking device 144 may be used with another input device (e.g.,the buttons 114 and 116 or touch-screen 46) to record one or morelocations of the device 42 to allow the system 12 to calculate varioussystem operational parameters or to setup the desired imaging sequence.Further, the tracking device 144 may be used by the imaging system 12 tomonitor the presence of the handheld interface device 42 within theoperative range of system 12. If the handheld interface device 42 ismoved outside the operative range of the system 12, the system 12 maysend a command to the device 42 to generate an audible tone via thespeaker 120.

Similar to device 40, the handheld interface device 42 may include otherdevices 142 besides the input and output devices described above foroperation of the device 42. All of these devices may be used separatelyor in combination to receive input commands for the operation of theimaging system 12 and to transmit these commands to the system 12 forexecution.

As mentioned above, the handheld interface device 38 is configured toreceive system operational data wirelessly communicated from the imagingsystem 12 and to provide a user detectable indication of the imagingsystem operational status based on the data. FIG. 8 illustrates anexemplary type of system operational data 146 received by the handheldinterface device 38 by the imaging system 12. The types of systemoperational data 146 illustrated are only examples and other types ofsystem operational data 146 may be presented. The system operationaldata 146 includes a locator signal 148 when the handheld interfacedevice 38 cannot be found by the user. Other system operational data 146includes X-ray source settings 150. These may include a kilovolt peaksetting, a milliamp setting, and a milliamp-second setting. The systemoperational data 146 includes a dose area product 152. The dose areaproduct 152 reflects the dosage of radiation, as well as the volume oftissue irradiated, with each image sequence. Also, an execution of acurrent exposure 154 is included. The system 12 ceases transmitting thisparticular system operational data 146 when the exposure execution 154concludes. When operation of the X-ray source 16 is inhibited, thedevice 38 receives an X-ray source inhibit 156, as described above.Further, the system operational data 146 includes a system charge status158 for the power supply 78 of the imaging system 12 that powers theX-ray source 16 and the mobile drive unit 82 (in mobile systems).

Besides receiving system operational data 146, the handheld interfacedevice 38 may also be configured to receive user-input commands foroperation of the imaging system 12. FIG. 9 illustrates varioususer-input and/or user-input commands 160 received by the handheldinterface device 38 and wirelessly transmitted to the imaging system 12.As previously mentioned, the user-input commands 160 include X-raysource settings 150. The command for X-ray source settings 150 mayinclude settings for exposure parameters of the X-ray source 16, such asthe kilovolt peak setting, the milliamp setting, the milliamp-secondsetting, a focal spot selection, source-to-image distance,source-to-patient distance, and orthogonality. Also, user-input commands160 include movement of the X-ray source 16. This movement may includethe movement of a remotely movable X-ray source 16 to a desired positionvia either the movement of the overhead tube support arm 14 in fixedsystem 12 or the movement of the support arm 52 and/or support column 54in a mobile system 12. The user-input commands 160 also include amovement command 164 for fine movement of the mobile system 12 via thewheeled base 58. As previously mentioned, the user-input commands 160include a collimator light command 166 to illuminate the collimatorlight 66 on the region of the patient 20 that will receive X-rayradiation during an imaging sequence.

Also, patient audible commands 168 may include a signal from the device38 to the imaging system 12 to transmit the patient-audible command 168in response to the signal. These signals may correspond to multiplepre-recorded patient audible commands 168 stored within the controlcircuitry 74 of the system 12. Moreover, the patient-audible commands168 may be pre-recorded in at least two spoken languages. Thepatient-audible commands 168 may be transmitted via the system speaker44. A user, then, who does not speak a particular language maynevertheless issue instructions to the patient in the patient's languagesimply by selecting the desired instructional message via the handhelddevice. Also, as mentioned above, certain embodiments of the handheldinterface device 38 (e.g., 42) may be configured to receive, to record,and/or transmit user-dictated voice inputs 170. The transmitteduser-dictated voice inputs 170 may be received by the imaging system 12and emitted for the patient 20 undergoing X-ray imaging to hear.

FIGS. 10-17 that follow illustrate various scenarios for the use of thehandheld interface device 38 and/or interaction with the imaging system12. FIG. 10 illustrates a scenario where the handheld interface device38 and the imaging system 12 are outside a desired range. The imagingsystem 12 illustrated is mobile, but the system 12 may also be fixed.The imaging system 12 and/or the handheld interface device 38 areconfigured to determine the strength of the wireless signals betweeneach other. A preset desired wireless strength that corresponds to aspecific distance between the device 38 and the system 12 may be set.This preset desired wireless strength may vary depending upon the setupof the X-ray system 10. As the user 36 moves away from the system 12with the device 38 the wireless strength decreases. If the wirelessstrength falls below the preset desired wireless strength, then theimaging system 12 and/or the handheld interface device 38 are configuredto emit a user-perceptible signal (e.g., audible tone via speakers 44,104, and/or 120) to indicate that the system 12 and the device 38 aregreater than a desired distance apart.

As mentioned above, certain embodiments of the handheld interface device38 (e.g., 42) may include tracking devices 144 or the device may beconfigured to perform tracking based on signal strength, or a similarparameter. FIG. 11 illustrates a scenario where the tracking device 144allows the imaging system 12 to follow the handheld interface device 38.The imaging system 12 illustrated is a mobile system. The imaging system12 is configured to track the location and/or movement of the handheldinterface device via the tracking device 144 located within device 38.The user 36 may input a command via one of the input devices availableon the handheld interface device 38 (e.g., screen 46) for the system 12to follow the device 38. As the user 36 moves throughout a building, thesystem 12 tracks the location of the handheld interface device 38 viathe tracking device 144 and follows the device 38 as it is displaced.This may dispense with the need for the system to be guided, pushed ordriven for at least some of its movement through an institution.

Another use for the tracking device 144 of the handheld interface device38 is shown in FIG. 12. FIG. 12 illustrates the imaging system 12 withthe patient 20 located on the table 26 between the X-ray source 16 andthe image receptor 22. The imaging system 12 may be a fixed or mobilesystem. The X-ray source 16 may be moved to a desired position viaeither the movement of the overhead tube support arm 14 in the fixedsystem 12 or the movement of the support arm 52 and/or support column 54in the mobile system 12. As above, the user may input a command via oneof the input devices available on the handheld interface device 38(e.g., screen 46) for the system 12 to move the X-ray source 16 basedupon the location and/ or movement of the handheld interface device 38to the desired position. As the handheld interface device 38 is movedwithin a 3-D coordinate system along an x, y, and z axes, the X-raysource 16 is correspondingly moved along the same axes to the desiredposition.

The tracking device 144 can also similarly be used to provide an inputto the imaging system 12 to perform a desired X-ray image dataacquisition sequence. FIG. 13 illustrates the use of the handheldinterface device 38 to perform a desired imaging sequence. Theillustrated imaging system 12 is as described in FIG. 12. The user 36may select an image acquisition sequence mode via one of the inputdevices available on the handheld interface device 38 (e.g., screen 46).Once in the acquisition mode, the imaging system 12 is configured torecord one or more locations of the handheld interface device 38 via thetracking device 144 and to use the recorded locations as input for anX-ray imaging sequence. The recorded locations may be used as inputs fordetermining a tomographic sweep by the X-ray source 16. For example,using the input devices on the handheld interface device 38, a firstlocation, A, may be selected and then recorded by the system 12. Then,similarly the device 38 may be used to select a second location, B, tobe recorded by the system 12. Upon initiation of the X-ray imagingsequence, the radiation source 16 moves between locations A and Bperforming the desired imaging sequence (e.g., tomographic sweep)generating multiple images 172 between those locations.

FIG. 14 illustrates the use of the handheld interface device 38 tocompute various exposure parameters. The imaging system 12 illustratedis as described in FIG. 12. The handheld interface device 38 and thetracking device 144 may be used to input the location of the device 38as described above. The imaging system 12 is configured to use thelocation of the device 38 for the computation of various exposureparameters, such as source-to-image distance (SID) 174, source-topatient distance 176, and patient thickness 178. The SID 176 isdetermined by placing the handheld interface device 38 at the imagereceptor 22 and inputting the location of the device 38 (location A).The system 12 uses location A with respect to the X-ray source 16 in thecomputation of SID 176. The source-to-patient distance 176 is similarlydetermined by placing the handheld interface device 38 on the patient 20where the exposure is to take place and inputting the location of thedevice 38 (location B). The imaging system 12 then takes the differencebetween the source-to patient distance 176 and the SID 174 for thecomputation of the patient thickness 178. The patient thickness 178 maybe used by the imaging system 12 to set an X-ray dose parameter for theexposure.

FIG. 15 illustrates a further use of the handheld interface device 38.The imaging system 12 is illustrated with the patient 20 located on aninclined surface 180 (e.g., bed 60) between the X-ray source 16 and theimage receptor 22. The image receptor 22 may have a grid 182 located onthe image receptor 22 to reduce the scattering of the X-rays. Theimaging system 12 may be a fixed or mobile system. The X-ray source 16may be moved to a desired position via either the movement of theoverhead tube support arm 14 in the fixed system 12 or the movement ofthe support arm 52 and/or support column 54 in a mobile system 12. Asabove, the user places the handheld interface device 38 on the imagereceptor 22 and/or grid 182 and inputs a command via one of the inputdevices to transmit the location of the device 38 as derived from thetracking device 144 and thus the relative location of the image receptor22 and/or grid 182 to the system 12. The inputted location of thehandheld interface device 38 is used to compute the orthogonalitybetween the image receptor 22 and/or grid 182 with respect to the X-raysource 16. The calculated orthonogonality is displayed on the screen 46of the handheld interface device 38. Based on the calculatedorthogonality the imaging system 12 also may move the X-ray source 16along a desired x, y, and z axes. For example, the X-ray source may beinitially positioned in a first position, A. After determining theorthogonality between the X-ray source 16 and image receptor 22 and/orgrid 182, the system 12 may move the X-ray source 16 to a secondposition, B, with the desired orthogonality.

The handheld interface device 38 has additional features. In embodimentsof the handheld interface device 38 with a screen 46 (e.g., 42), thescreen 46 is configured to display patient data 184 as illustrated inFIG. 16. Types of patient data 184 include an identifying image 186 ofthe patient 20. The identifying image 186 may be provided via thenetwork 48 or the imaging system 12. The system 12 may also provide animage 188 of the patient 20 or a portion of the anatomy of the patient20 to receive X-ray radiation via the system camera 24. The image 188may be a still or live image. Also, the image 188 may be a generic imagerepresentative of an anatomical region of the patient 20. Additionalpatient data 184 displayed by the screen includes patient identifyingdata 190 such as the name of the patient, the anatomy to be imaged, thetypes of images, and further instructions or information. The screen 46also displays reconstructed X-ray images 192 of the patient 20 receivedfrom the system 12 (in digital X-ray systems 10).

FIG. 17 illustrates the use of the screen 46 to control the movement ofthe X-ray source 16. The illustrated imaging system 12 is as describedabove. The user receives the image 188 of the patient 20 on the screen46 of the handheld interface device 46. The screen 46 illustrated istouch-screen 46 capable of encoding inputs by the touch of the user. Theuser uses a finger or other object 194 to input a selection 196 of aspecific part of the patient anatomy for exposure. The device 38transmits a signal to the imaging system 12 specifying the desiredanatomy for exposure to X-ray radiation. The imaging system 12 isconfigured to move the X-ray source 16 into position to take the desiredexposure. Then, the system 12 (in a digital X-ray system 10) isconfigured to process X-ray image data and to generate the reconstructedimage 192 of the desired anatomy. The screen 46 of the handheldinterface device 38 displays the reconstructed image 192 of the desiredanatomy.

FIGS. 18-21 illustrate various methods for operation of the handheldinterface device 38. FIG. 18 illustrates a flow diagram of a method 198for operating the handheld interface device 38. The method 198 includesestablishing wireless communication between the imaging system 12 andthe handheld interface device 38 (block 200). The system 12 includes thecomponents described above in FIG. 3. The imaging system 12 and thehandheld interface device 38 communicate via their respective wirelessinterfaces 76 and 124. Following the establishment of a wireless link,system 12 communicates system operational data 146 to the handheldinterface device 38 (block 202). The handheld interface device 38 thenprovides a user detectable indication of the operational status of theimaging system 12 based upon the received data 146 (block 204). The userdetectable indication includes vibration of the device 38, illuminationfrom LEDS, among other indications.

FIG. 19 illustrates another flow diagram of a method 206 for operatingthe handheld interface device 38. The method 206 includes establishingwireless communication between the system 12 and device 38 (block 208)as described in method 198. After establishing a wireless link, the userinputs a command into the handheld interface device 38 for operation ofthe imaging system 12 (block 210). The user-input command 160 mayinclude the movement of the X-ray source 16 or the fine movement of thesystem 12, if mobile, as an example. Following input of the command, thehandheld interface device 38 wirelessly transmits the command to thesystem (block 212), whereupon the imaging system 12 is configured toreceive and execute the command for operation of the system 12.

FIG. 20 illustrates a flow diagram of a method 214 for viewing patientdata on a handheld interface device 38. The method 214 includesestablishing wireless communication between the system 12 and device 38(block 216) as described in method 198. The handheld interface device 38includes user-viewable screen 46 configured to display patient data 184and to receive a user input (e.g., touch-screen 46). After establishinga wireless link, the handheld interface device receives patient data 184either from the imaging system 12 or the HIS 88 or RIS 86 of the medicalfacility's network 48 (block 218). The imaging 12 may also transmit theimage 188 of the patient 20 or anatomical region of the patient 20 tothe device 38 (block 220) via the system camera 24. Alternatively, theimage 188 (e.g., generic image representative of anatomical region ofpatient 20) may be provided by the network 48. After receiving thepatient data 184, the data 184 is displayed on the screen 46 (block222). If the patient data consists of the image 188 of the patient 20,the user may select a desired portion of the anatomy for exposure (block224). The selection 196 may be transmitted as a signal to the system 12(block 226) for that region to be imaged. In response to the signal, theX-ray source 16 may need to be moved to make the desired exposure. Thesystem 12 (in a digital X-ray system 10) may then acquire and processX-ray image data of the selected anatomy (block 228). Then, the system12 may generate a reconstructed X-ray image 192 (block 230). Thisreconstructed X-ray image 192 may be transmitted to and displayed on thescreen 46 of the handheld interface device 38 (block 232).

FIG. 21 illustrates a flow diagram of a method 234 for tracking thelocation of the handheld interface device 38. The method 234 includesestablishing wireless communication between the system 12 and device 38(block 236) as described in method 198. The handheld interface device 38includes tracking device 144 which is configured to provide a locationand to track movement of the handheld interface device. Afterestablishing a wireless link, the tracked location and/or movement ofthe handheld interface device 38 is transmitted to the imaging system 12(block 238). The imaging system 12 then uses the tracked location and/orposition as input to control at least one function of the system 12(block 240). For example, the input may be used to direct the system 12,if mobile, to follow the handheld interface device 38.

The handheld interface device 38 described above provides the userincreased information about the imaging system 12 while allowing theuser to work at a distance from the system 12 and providing a saferenvironment. The wireless design alleviates the problems typicallyassociated with a cord, such as interference with medical equipment ordamage to the cord over time. Additionally, the user may find the device38 if ever lost via a locator signal. Further, the device 38 providesthe user three different types of feedback mechanisms to indicate acurrent exposure including visual, audible, and tactile (vibrations).

The more advanced features of the handheld interface device 38 providethe user more flexibility in controlling the system 12, particularly inlight of advanced user control features provided by the touch-screen 46and the tracking device 144. For example, the advanced features wouldassist in allowing the user to better position the system 12 and imagereceptor 22, particularly when the patient 20 is in a complicatedposition, for acquiring an improved image.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. An X-ray system comprising: an imaging system including a source ofX-ray radiation, an X-ray image receptor, control circuitry forcontrolling the source of X-ray radiation, and a wireless interface; anda handheld interface device configured to communicate wirelessly withthe imaging system; wherein the imaging system is configured to track alocation of the handheld interface device and to use the location as aninput for at least one control function of the imaging system.
 2. Thesystem of claim 1, wherein the imaging system is mobile, and isconfigured to follow the handheld interface device as it is displaced ina building.
 3. The system of claim 1, wherein the imaging system isconfigured to command movement of the X-ray source based upon thelocation of the handheld interface device.
 4. The system of claim 1,wherein the imaging system is configured to record at least one locationof the handheld interface device and to use the recorded location as aninput for an X-ray image acquisition sequence.
 5. The system of claim 4,wherein the imaging system is configured to record a plurality oflocations of the handheld interface device and to use the recordedlocations as inputs for determining a tomographic sweep by the X-raysource.
 6. The system of claim 1, wherein the imaging system isconfigured to use the location of the handheld interface device forcomputation of a source-to-image distance.
 7. The system of claim 6,wherein the imaging system is configured to use a further location ofthe handheld interface device for computation of a source-to-patientdistance.
 8. The system of claim 7, wherein the imaging system isconfigured to use the source-to-image distance and the source-to-patientdistance for computation of a patient thickness.
 9. The system of claim8, wherein the imaging system is configured to use the computed patientthickness to set an X-ray dose parameter.
 10. The system of claim 1,wherein the imaging system is configured to use a location of thehandheld interface device for computation of orthogonality between theimage receptor and the X-ray source.
 11. An X-ray system comprising: ahandheld X-ray interface device comprising a wireless interface forcommunicating with an imaging system and a tracking device configured toprovide a location and/or to track movement of the handheld X-rayinterface device relative to the imaging system, wherein the location ortracked movement of the handheld X-ray interface device is communicatedto the imaging system as an input for at least one control function ofthe imaging system.
 12. The system of claim 11, wherein the trackingdevice comprises an accelerometer, a magnetometer, an inclinometer, or agyroscope.
 13. The system of claim 11, wherein the handheld X-rayinterface device is configured to command movement of the imaging systemvia the location or tracked movement of the handheld X-ray interfacedevice.
 14. The system of claim 11, wherein the handheld X-ray interfacedevice is configured to command the imaging system to perform a specificX-ray image acquisition sequence via the location or tracked movement ofthe handheld X-ray interface device.
 15. The system of claim 11, whereinthe handheld X-ray interface device is configured to provide thelocation of the handheld X-ray interface device to the imaging systemfor computation of a source-to-image distance.
 16. The system of claim15, wherein the handheld X-ray interface device is configured to providea further location of the handheld X-ray interface device to the imagingsystem for computation of a source-to-patient distance.
 17. The systemof claim 11, wherein the handheld X-ray interface device comprises aninput device configured to indicate to the imaging system to record thelocation of the handheld X-ray interface device.
 18. A method fortracking the location of a handheld interface device, comprising:establishing wireless communication between an imaging system and ahandheld interface device, the imaging system comprising a source ofX-ray radiation, an X-ray image receptor, control circuitry forcontrolling the source of X-ray radiation, and a first wirelessinterface, the handheld interface device comprising a second wirelessinterface for communicating wirelessly with the imaging system and atracking device configured to provide a location and to track movementof the handheld interface device; and transmitting the location ortracked movement of the handheld interface device relative to theimaging system.
 19. The method of claim 18, using the location ortracked movement of the handheld interface device as an input to controlat least one function of the imaging system.
 20. The method of claim 19,wherein the imaging system is mobile, and is configured to follow thehandheld interface device as it is displaced in a building.